Greenberg et al. in U.S. Pat. No. 4,401,677 disclose that various mercaptoalkanoyl .alpha.-amino acids are useful analgesic agents due to their enkephalinase inhibition activity.
Ondetti et al. in U.S. Pat. No. 4,053,651 disclose that various mercaptoalkanoyl and acylmercaptoalkanoyl .alpha.-aminoacids are useful hypotensive agents due to their angiotensin converting enzyme inhibition activity.
Roques et al. (Nature, Vol. 288, Nov. 1980, p.286-288) disclose that thiorphan, [(D,L)-3-mercapto-2-benzylpropanoyl]-glycine, is an inhibitor of enkephalinase in vitro in nanomolar concentration and in vivo after either intracerebroventricular or systemic administration.
Roques et al. in European Patent Application No. 38.758 disclose various .alpha.-amino acid derivatives including mercaptoalkanoyl and acylmercaptoalkanoyl derivatives as possessing enkephalinase inhibition activity.
Mumford et al. (Biochemical And Biophysical Research Comm., Vol. 109, No. 4, 1982, p. 1303-1309) disclose that various substituted N-carboxymethyl dipeptides including those having a terminal .beta.-alanine group possess enkephalinase inhibition activity.
Berger et al. in European Patent Application No. 54,862 disclose enkephalinase inhibiting peptides of the formula ##STR2## wherein R.sub.2 is a carboxylic or phosphonic acid or ester and y is zero or an integer from 1 to 3.
Cushman et al. (Biochemistry, Vol. 16, No. 25, 1977, p. 5484-5491) disclose various carboxyalkanoyl and mercaptoalkanoyl amino acids as angiotensin converting enzyme inhibitors. Among the compounds disclosed is ##STR3##
Sundeen et al. in U.S. Pat. Nos. 4,235,885 and 4,297,275 disclose mammalian collagenase inhibitors including mercaptoalkanoyl and acylmercaptoalkanoyl compounds of the formula ##STR4## wherein m is zero or an integer from 1 to 9, R.sub.3 includes hydrogen, and R.sub.4 includes hydroxy and amino.
Sundeen et al. in U.S. Pat. No. 4,327,111 disclose mammalian collagenase inhibitors including mercaptoalkanoyl and acylmercaptoalkanoyl compounds of the formula ##STR5## wherein R.sub.4 is hydrogen, alkyl or aryl, n is an integer from 1 to 20, and R.sub.3 is alkyl of 3 to 8 carbons, cycloalkyl of 3 to 7 carbons, aryl, or arylalkyl.